4-Chlorobenzoic Acid → 4-Chloro-3-(chlorosulphonyl)benzoic acid

Participants

Reaction Conditions

Reaction Steps

A round bottom flask was charged with chlorosulfonic acid (6.36 g, 96.0 mmol) at 0° C. and 4-chloro benzoic acid was added portion wise. The reaction mixture was heated at 130° C. for 5 h. The reaction mixture was then poured over ice and stirred for 10 minutes. The solids formed were filtered, washed with cold water and dried to afford 4-chloro-3-(chlorosulfonyl)benzoic acid as a white powder. This compound was then charged into a round bottom flask containing sodium sulfite (7.1 g, 56.4 mmol) and water (40 mL) portion wise. Aqueous sodium hydroxide (6 N) was then added drop wise till the pH of the reaction mixture reaches 10 and the reaction was stirred over night. The reaction was then made acidic (pH 2) by addition of 2N HCl. The solids formed were filtered and dried to get the title compound as a white solid.

Provenance & Evidence